Using a plane subdivide once in edit mode (to produce the center edge), bent at a right angle, and a subdivide modifier set to viewport = 7. Note: Further testing shows that the level of subdivision is irrelevant; even 1 works.

As @Alaska (Alaska) wrote, increasing the quality will increase the range that the edge crease setting has an effect.

Quality

Edge crease stopping point

3

0.56

4

0.64

5

0.71

6

0.78

7

0.84

8

0.90

9

0.95

10

full range

Tested using 2.90.2 8f21f867e715

As there is a setting specifically to control this effect, and it is documented (see the below links), I will close this report. EDIT: I was too slow. =)

@Evan Wilson (EAW)
The first thing I did — read manual. And there is no mention of such effect. And no such table.
So i think, there should be some words about it in crease-section.

And this useful table too.

Quality

Edge crease stopping point

…

…

Evan Wilson (EAW) renamed this task from Edge crease effect stucks at 0.57 to The relationship between Edge crease sharpness and the Quality setting is not specified in the manual like it is in the 2.80 release notes..Fri, May 22, 4:37 PM

@Vyacheslav (hitrpr) I just made that table. I have a feeling that the values will be different for different topology, so I don't think it could be added to to the manual. I will test to confirm this later.